Green Fleet

GM to Upgrade Volt to Protect Battery and Related Coolant System

January 5, 2012
• by Staff

The structural enhancements more evenly distribute crash energy following a severe side impact, according to GM.

WARREN, MI – General Motors said it will enhance the Chevrolet Volt’s structure and battery coolant system to further protect the battery from a possible electrical fire occurring days or weeks after a crash. GM said it is adding these enhancements following a National Highway Traffic Safety Administration (NHTSA) “preliminary evaluation” to examine post-crash battery performance.

The modifications include the following measures: First, GM is strengthening an existing portion of the Volt’s vehicle safety structure to further protect the battery pack in a severe side collision. Next, the automaker is adding a sensor in the reservoir of the battery coolant system to monitor coolant levels. Lastly, GM is adding a tamper-resistant bracket to the top of the battery coolant reservoir to help prevent potential coolant overfill.

GM stated it conducted four crash tests between Dec. 9 and 21 of Volts with the structural enhancement, and that the enhancement performed as intended. The battery pack wasn’t damaged via intrusion during the crash tests, and no coolant leakage occurred, according to GM.

General Motors is adding a tamper-resistant bracket to the top of the battery coolant reservoir to prevent potential coolant overfill.

The National Highway Traffic Safety Administration (NHTSA) also released a statement on Jan. 5. NHTSA reported that based on testing the Volt, equipped with GM's upgrades, on Dec. 22, 2011, the results also showed no intrusion into the vehicle’s battery compartment and no apparent coolant leakage. NHTSA said that under the observation of GM representatives, and in working with experts from the Department of Energy and the Department of Defense, both battery intrusion and coolant leakage must be present to cause a post-crash fire in the Volt.

The organization said it plans to complete its analysis of the overall research in the next few weeks and make its conclusions public after it closes the investigation.

The automaker is also installing a battery-coolant sensor to monitor coolant levels in the battery cooling system.

“The Volt has always been safe to drive. Now, we will go the extra mile to ensure our customers’ peace of mind in the days and weeks following a severe crash,” said Mary Barra, GM senior vice president of Global Product Development. These enhancements and modifications will address the concerns raised by the severe crash tests. There are no changes to the Volt battery pack or cell chemistry as a result of these actions. We have tested the Volt’s battery system for more than 285,000 hours, or 25 years, of operation. We’re as confident as ever that the cell design is among the safest on the market.”